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[S390] implement interrupt-enabling rwlocks

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arch backend for f5f7eac41d
"Allow rwlocks to re-enable interrupts".

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Heiko Carstens 2009-06-12 10:26:22 +02:00 committed by Martin Schwidefsky
parent 76d4e00a05
commit ce58ae6f7f
2 changed files with 56 additions and 3 deletions
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19
arch/s390/include/asm/spinlock.h
View File

@ -122,8 +122,10 @@ static inline void __raw_spin_unlock(raw_spinlock_t *lp)
#define __raw_write_can_lock(x) ((x)->lock == 0)
extern void _raw_read_lock_wait(raw_rwlock_t *lp);
extern void _raw_read_lock_wait_flags(raw_rwlock_t *lp, unsigned long flags);
extern int _raw_read_trylock_retry(raw_rwlock_t *lp);
extern void _raw_write_lock_wait(raw_rwlock_t *lp);
extern void _raw_write_lock_wait_flags(raw_rwlock_t *lp, unsigned long flags);
extern int _raw_write_trylock_retry(raw_rwlock_t *lp);
static inline void __raw_read_lock(raw_rwlock_t *rw)
@ -134,6 +136,14 @@ static inline void __raw_read_lock(raw_rwlock_t *rw)
_raw_read_lock_wait(rw);
}
static inline void __raw_read_lock_flags(raw_rwlock_t *rw, unsigned long flags)
{
unsigned int old;
old = rw->lock & 0x7fffffffU;
if (_raw_compare_and_swap(&rw->lock, old, old + 1) != old)
_raw_read_lock_wait_flags(rw, flags);
}
static inline void __raw_read_unlock(raw_rwlock_t *rw)
{
unsigned int old, cmp;
@ -151,6 +161,12 @@ static inline void __raw_write_lock(raw_rwlock_t *rw)
_raw_write_lock_wait(rw);
}
static inline void __raw_write_lock_flags(raw_rwlock_t *rw, unsigned long flags)
{
if (unlikely(_raw_compare_and_swap(&rw->lock, 0, 0x80000000) != 0))
_raw_write_lock_wait_flags(rw, flags);
}
static inline void __raw_write_unlock(raw_rwlock_t *rw)
{
_raw_compare_and_swap(&rw->lock, 0x80000000, 0);
@ -172,9 +188,6 @@ static inline int __raw_write_trylock(raw_rwlock_t *rw)
return _raw_write_trylock_retry(rw);
}
#define __raw_read_lock_flags(lock, flags) __raw_read_lock(lock)
#define __raw_write_lock_flags(lock, flags) __raw_write_lock(lock)
#define _raw_read_relax(lock) cpu_relax()
#define _raw_write_relax(lock) cpu_relax()

40
arch/s390/lib/spinlock.c
View File

@ -124,6 +124,27 @@ void _raw_read_lock_wait(raw_rwlock_t *rw)
}
EXPORT_SYMBOL(_raw_read_lock_wait);
void _raw_read_lock_wait_flags(raw_rwlock_t *rw, unsigned long flags)
{
unsigned int old;
int count = spin_retry;
local_irq_restore(flags);
while (1) {
if (count-- <= 0) {
_raw_yield();
count = spin_retry;
}
if (!__raw_read_can_lock(rw))
continue;
old = rw->lock & 0x7fffffffU;
local_irq_disable();
if (_raw_compare_and_swap(&rw->lock, old, old + 1) == old)
return;
}
}
EXPORT_SYMBOL(_raw_read_lock_wait_flags);
int _raw_read_trylock_retry(raw_rwlock_t *rw)
{
unsigned int old;
@ -157,6 +178,25 @@ void _raw_write_lock_wait(raw_rwlock_t *rw)
}
EXPORT_SYMBOL(_raw_write_lock_wait);
void _raw_write_lock_wait_flags(raw_rwlock_t *rw, unsigned long flags)
{
int count = spin_retry;
local_irq_restore(flags);
while (1) {
if (count-- <= 0) {
_raw_yield();
count = spin_retry;
}
if (!__raw_write_can_lock(rw))
continue;
local_irq_disable();
if (_raw_compare_and_swap(&rw->lock, 0, 0x80000000) == 0)
return;
}
}
EXPORT_SYMBOL(_raw_write_lock_wait_flags);
int _raw_write_trylock_retry(raw_rwlock_t *rw)
{
int count = spin_retry;